call reminiscent of the European Chiffchaff, recorded from a tall bush near the edge of a mature forest. Chiffchaffs do not normally reach southern Nigeria. Nearby several Yellow Wagtails ssp. thunbergi were present, but their calls would be sharper. Any local birds with a similar call?
Forum discussion concluded this was most likely calls of Collared Sunbird, a species that also had been seen at the recording site around that time.